The present invention relates to a motorcycle tire, more particularly to a combination of a tread pattern and tread profile capable of improving the rolling resistance of the tire.
In view of the recent global environmental problems such as global warming and depletion of the ozone layer, in order to improve fuel economy of the vehicles (the distance traveled per unit of fuel used), pneumatic tires are required to have low rolling resistance. This is also true of motorcycle tires.
In the US Patent Application Publication No. US-2006-207701-A1, a motorcycle tire is disclosed, wherein the tread portion is provided in its center region with a low-hysteresis-loss tread rubber having a relatively small loss tangent tan δ. Therefore, heat generation of the tread rubber and energy loss during straight running are decreased, and the rolling resistance can be reduced.
In the case of such a low-hysteresis-loss tread rubber, however, there is a tendency that the road grip performance and steering stability become not so good.
On the other hand, it is conceivable to decrease the rolling resistance by using a high-modulus tread rubber in the tread portion. In this case, flexural deformation of the tread portion decreases, and the rolling resistance is decreased. But, the ride comfort and road grip performance are liable to deteriorate.